1. SPIROMETRY IN PRIMARY CARE
IMAD SHAWA, MD, FCCP
DIRECTOR OF CRITICAL CARE
CHAIRMAN OF MEDICINE
FRANCISACN HEALTH-INDIANAPOLIS

2. I have no relevant financial relationships to disclose.
disclosures

4. Respiratory pump
Cardiac pump
Air-Blood interface
Basic physiology

5. Respiratory system Two balloons connected to air ducts
Air is pumped into contact with the blood (Alveolar Capillary interface)
Air is pumped back out
Respiratory system

6. THE LUNGS

7. Respiratory system Balloon Size & amount of air: Air ducts:
Spirometry
Lung Volumes
Air ducts:
Airway resistance
Air/Blood interface:
Diffusion
Pump strength neuromuscular test
Respiratory system

8. Spirometry

9. What is Spirometry?
Spirometry is a method of assessing lung function by measuring the total volume of air the patient can expel from the lungs after a maximal inhalation.

10. Flow Measuring Spirometer

11. Lung Volume Terminology

12. Lung Volume Terminology
Inspiratory reserve
volume
Inspiratory
capacity
Total
lung
capacity
Tidal volume
Expiratory reserve
volume
Vital
capacity
Residual volume

13. Standard Spirometric Indicies
FEV1 - Forced expiratory volume in one second:
The volume of air expired in the first second of the blow
FVC - Forced vital capacity:
The total volume of air that can be forcibly exhaled in one breath
FEV1/FVC ratio:
The fraction of air exhaled in the first second relative to the total volume exhaled

14. Additional Spirometric Indicies
VC - Vital capacity:
A volume of a full breath exhaled in the patient’s own time and not forced. Often slightly greater than the FVC, particularly in COPD
FEV6 – Forced expired volume in six seconds:
Often approximates the FVC. Easier to perform in older and COPD patients but role in COPD diagnosis remains under investigation
MEFR – Mid-expiratory flow rates:
Derived from the mid portion of the flow volume curve but is not useful for COPD diagnosis

15. Indications Evaluation of Dyspnea Evaluation of cough
Recognition of COPD in asymptomatic smokers
Diagnosis of Obstructive and restrictive lung Dz
Evaluation of response to Rx
Surveillance for drug induced lung toxicity
Pre-Op evaluation
Neuro-Muscular weakness
Disability evaluation
Indications

16. Types of Spirometers Bellows spirometers:
Measure volume; mainly in lung function units
Electronic desk top spirometers:
Measure flow and volume with real time display
Small hand-held spirometers:
Inexpensive and quick to use but no print out

17. Volume Measuring Spirometer

18. Desktop Electronic Spirometers

19. Small Hand-held Spirometers

20. Spirometry Predicted Normal Values

21. Predicted Normal Values
Affected by:
Age
Height
Sex
Ethnic Origin

22. Criteria for Normal Post-bronchodilator Spirometry
FEV1: % predicted > 80%
FVC: % predicted > 80%
FEV1/FVC: > , depending on age

23. Mixed Obstructive and Restrictive
Spirogram Patterns
Normal
Obstructive
Restrictive
Mixed Obstructive and Restrictive

24. Normal Trace Showing FEV1 and FVC5 4
FEV1 = 4L
FVC = 5L
FEV1/FVC = 0.8
Volume, liters 3 2 1 1 1 2 3 4 5 6
Time, sec

25. SPIROMETRY
OBSTRUCTIVE DISEASE

26. Spirometry: Obstructive Disease
Normal 5 4 3
Volume, liters
FEV1 = 1.8L
FVC = 3.2L
FEV1/FVC = 0.56 2
Obstructive 1 1 2 3 4 5 6
Time, seconds

27. Bronchodilator Reversibility Testing
Provides the best achievable FEV1 (and FVC)
Helps to differentiate COPD from asthma
Must be interpreted with clinical history - neither asthma nor COPD are diagnosed on spirometry alone

28. SPIROMETRY
RESTRICTIVE DISEASE

29. Criteria: Restrictive Disease
FEV1: normal or mildly reduced
FVC: < 80% predicted
FEV1/FVC: > 0.7

30. Spirometry: Restrictive Disease
Normal 5 4 3
Volume, liters
Restrictive
FEV1 = 1.9L
FVC = 2.0L
FEV1/FVC = 0.95 2 1 1 2 3 4 5 6
Time, seconds

31. Mixed Obstructive/Restrictive
FEV1: < 80% predicted
FVC: < 80% predicted
FEV1 /FVC: < 0.7

32. Mixed Obstructive and Restrictive
Normal
Volume, liters
FEV1 = 0.5L
FVC = 1.5L
FEV1/FVC = 0.30
Obstructive - Restrictive
Time, seconds
Restrictive and mixed obstructive-restrictive are difficult to diagnose by spirometry alone; full respiratory function tests are usually required
(e.g., body plethysmography, etc)

33. SPIROMETRY
Flow Volume

34. Flow Volume Curve Standard on most desk-top spirometers
Adds more information than volume time curve
Less understood but not too difficult to interpret
Better at demonstrating mild airflow obstruction

35. Flow Volume Curve Maximum expiratory flow (PEF) FVC Volume (L)
Expiratory flow rate
L/sec
FVC RV
TLC
Inspiratory flow rate
L/sec
Volume (L)

36. Flow Volume Curve Patterns Obstructive and Restrictive
Severe obstructive
Restrictive
Expiratory flow rate
Expiratory flow rate
Expiratory flow rate
Volume (L)
Volume (L)
Volume (L)
Reduced peak flow, scooped out mid-curve
Steeple pattern, reduced peak flow, rapid fall off
Normal shape, normal peak flow, reduced volume

37. Spirometry: Abnormal Patterns
Obstructive
Restrictive
Mixed
Volume
Volume
Volume
Time
Time
Time
Slow rise, reduced volume expired; prolonged time to full expiration
Fast rise to plateau at reduced maximum volume
Slow rise to reduced maximum volume; measure static lung volumes and full PFT’s to confirm

38. Spirometry - Possible Side Effects
Feeling light-headed
Headache
Getting red in the face
Fainting: reduced venous return or vasovagal attack (reflex)
Transient urinary incontinence
Spirometry should be avoided after recent heart attack or stroke

39. Unacceptable Trace - Poor Effort
Normal
Volume, liters
Variable expiratory effort
Inadequate sustaining of effort
May be accompanied by a slow start
Time, seconds

40. Unacceptable Trace – Stop Early
Normal
Volume, liters
Time, seconds

41. Unacceptable Trace – Slow Start
Normal
Volume, liters
Time, seconds

42. Unacceptable Trace - Coughing
Normal
Volume, liters
Time, seconds

43. Unacceptable Trace – Extra Breath
Normal
Volume, liters
Time, seconds

44. Some Spirometry Resources
Global Initiative for Chronic Obstructive Lung Disease (GOLD) -
Spirometry in Practice -
ATS-ERS Taskforce: Standardization of Spirometry. ERJ 2005;29:
National Asthma Council: Spirometry Handbook

45. Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2010